This invention relates to connection of data terminals to a data network through wireless access points, and in particular to restoration of such access in the event of failure of a primary connection between an access point and the data network.
Connection to data networks such as the Internet has become an integral part of many domestic and small business activities. Typically, one or more user terminals will connect to the public network through a local area network (LAN) controlled by a router, which mediates data messages between the user terminal and the internet, including providing modem functions. Connection between the terminal and the router may be by an Ethernet or Powerline connection, but increasingly wireless connection is used (a Wireless LAN or WLAN) as this allows terminals to be placed anywhere within wireless range of the router.
Terminals connected to the same router may also communicate between each other without going through the external network. To provide privacy for such activity, and to ensure the router is not misused by unauthorised persons to gain access to the internet, routers typically have access protection to ensure only users with the correct access credentials can use it.
Public wireless access points also exist which allow any users with appropriate terminal equipment to connect to the Internet. These access points may be dedicated public access points provided by commercial enterprises to attract custom, or parts of the capacity of privately-owned access points made available to the public by their owners in exchange for reciprocal access rights to other participants' access points.
Failure of the primary connection between an access point and the network can be problematic as users have become reliant on their internet connections for many business and domestic purposes. In many cases a service provider's helpdesk, or a troubleshooting application, can guide the user to establish a replacement connection to the Internet through a public wireless access point whilst the fault in the primary connection is under repair.
Many troubleshooting operations can be provided by information available on the Internet, but if it is the Internet connection itself which has failed that information is not accessible unless the user has had the foresight to download it in advance. Consequently, such failures account for a very high proportion of calls to network operators' helpdesks—and in even that course of action may not be available if the Internet connection is over the user's telephone line, as the failure is likely to have affected voice calls over the telephone line as well.
The present invention provides a process to allow automatic re-establishment of connection between a user and the data network on detection of failure of the primary network.
It is known, in a related art, to provide for an access point, on detecting a failure of its backhaul (primary) connection, to generate redirection instructions to the wireless terminals currently connected to it. An example of this is described in United States patent application US2011/0032816. However, the system described therein presupposes that the access point has data stored therein relating to the alternative access points to which the terminals should attempt connection. Such an arrangement may be practical in a planned cellular telephone network, where the identities and locations of access points are predetermined by the network operator, and relatively permanent. However, in a network in which access points are under the control of individual users, the availability of such access points is more fluid and unpredictable. Users may move their access points around, or switch them off altogether. In many cases, the access points are provided primarily for the owner's own use, and public access is provided (with suitable firewall protection) only if, and to the extent that, the owner is not using the full capacity. It is therefore not possible, in general, to pre-programme specific redirection instructions in an access point for use in the event of failure of its primary backhaul connection. It is also known, for example from US patent application 2009/0213730, to provide each access point with multiple wireless interfaces, and using one of the multiple interfaces in each of two such access points to relay data between them. However, this arrangement not only requires both the access points to be fitted with multiple wireless interfaces, but also requires any users using one of these interfaces for any other purpose to lose their connection if the interface is to be used for relay purposes. Since each interface can only handle either local traffic or relay traffic, the amount of either traffic that can be handled cannot be allocated flexibly over the whole capacity of the access point.
The present invention provides a system for managing a failure situation (which, it is to be hoped, is a rare event) without any special equipment being required. In particular, the invention only requires special capabilities in the access point experiencing the loss of backhaul connection, such that it may connect to the network through any other access point, whether modified or not.
According to the present invention, there is provided a process for restoration of access between one or more data terminals and a data network by way of a first wireless-enabled access point in communication with the data terminals through a wireless interface after a primary connection between the first access point and the data network is lost, comprising the steps of                a) detecting loss of the primary connection to the data network        b) conducting a scan for a further wireless-enabled access point        c) establishing a wireless connection using the said wireless interface between the first access point and the further access point        d) attempting connection between the first access point and the data network by way of the further access point,        e) in the event of successful connection to the data network by the first access point, establishing connection between the one or more data terminals and the data network by way of the first and further access points.        
The invention also provides a wireless-enabled access point for connecting one or more user terminals to a data network, having a wireless interface to communicate with the user terminals and a second interface arranged to provide a primary connection to the data network, the access point having a connection monitor to detect loss of the primary connection, a scanner to detect the presence of one or more further wireless-enabled access points, and arranged to establish a wireless connection to the data network by way of the said wireless interface and one of the further wireless-enabled access points, and a switching processor for connecting user terminals to the data network by way of the further wireless-enabled access point.
In the preferred arrangement, the access point continues to monitor for availability of the primary connection to identify when connection by way of the primary connection becomes available, and restores its settings to effect such reconnection. The application may be arranged to defer such reconnection until any data session in progress has been completed.
The invention allows a router which loses its internet connection to automatically seek a neighbouring public wireless access point and connect to it in order to maintain an internet connection. In the preferred embodiment a message will be displayed on any user terminal connected to the access point to notify the user that the connection is defaulting to a different access route, as it may affect the available bandwidth. The user may also be advised to report the fault on the primary connection, or advised that the service provider is already aware of the fault.
The invention may be implemented by software installed in the access point, either on manufacture, or by subsequent upgrade of the programming of the access point by installation of software provided on a physical carrier (e.g. a CD-ROM) or by download over the internet connection.
It will be noted that the access point initiating the relay function may do so through any public access point still connected to the backhaul network. There is no requirement for that access point to be modified. It simply detects the initiating access point as if it were a normal user of the public wireless capability. The user will, of course, be handled like any other public user, for example being allocated lower priority than any dedicated users of the public access point.
In the preferred embodiment the access point is configured to suspend advertising its presence whilst the backhaul connection is unavailable. This will prevent further wireless devices attempting to connect to it, and will also prevent “loops” occurring, so that, for example, if two neighbouring access points both lose their respective primary connections they will not each attempt to restore connection through the other.
In a variant, once a first access point has successfully restored connection to the data network by way of a second access point that is itself still connected, the first access point may once again advertise its presence such that a third access point may, in turn, restore connection to the data network by way of the first and second access points, and so on. Each access point in the chain sees the next one upstream as a public user. However, each access point in the series would only have partial access to the capacity of the access point next in the series, so the capacity available to the access point furthest from the data network connection would be significantly less than that of those nearer to the data connection.